What speaker can I add to this head unit using the head power and factory original wiring to compilment the unit. I want to change out my original speakers qty 4, 5x7 speakers. What will work good with this head units power?

If you do upgrade your system and/or if you ever get a new vehicle be sure it has a glass breakage sensor. What happens in the grocery parking lot and park and fly lots is that the thieves break the window out and then reach inside and grab whatever they can reach, cell phones, GPS, laptops ect.. By not opening the door the car alarm doesn't go off and alert anyone. Whatever you do don't leave a GPS on the dash, the thieves just can't pass that up.

Just a thought. Also if you buy a Toyota or Honda with a factory alarm they can add the glass breakage sensor for just a little more at the dealership. I suspect that Ford is the same way although I am not sure.

Can't recommend a car alarm but remember to keep valuables out of sight and out of mind. Don't have your truck looking all flashy either. Just another plane jane (but clean, mind you!) F-150.... Nothing to see here. Let them look at the flashy cars with valuables on the dash and in the seats. Better thee than me.